The present invention relates to electrical connectors and power adapters, and, more particularly, to an electrical connector suitable for connecting an electronic device, such as a laptop computer, by way of a power adapter to an AC supply.
Many electronic devices operate with direct current (DC). However, most electrical transmission and/or distribution systems provide alternating current (AC). Accordingly, many electronic devices have an AC-to-DC power adapter, variously referred to as an AC adapter, wall adapter or charger, to convert AC power from an AC supply (e.g., the main electrical supply) to DC power that may be used to operate and/or charge the electronic device. Many power adapters consume standby power, that is, they consume power even though the electronic device may be disconnected, fully charged or turned off. Users routinely leave power adapters plugged in or otherwise connected to the AC supply. As a result, the widespread use of power adapters consumes a significant amount of standby power, which, in turn, provides little or no utility and effectively wastes electrical energy.
One known way of addressing this problem of power wastage is described in Applicant's co-pending U.S. patent application published under number US2011/0121656. US2011/0121656 discloses an AC-to-DC power adapter having circuitry that enables the adapter to operate in a power saving mode under certain conditions. A switch is provided for isolating the power conversion circuitry from the AC power supply, and a processor for controlling the switch. In one mode of operation, the processor operates to close the switch when the adapter is plugged into the electronic device requiring the DC power and to open the switch when the adapter is unplugged from the electronic device. In the latter case, the adapter consequently operates in a power-saving mode because even though the adapter remains connected to the AC supply, it is not drawing any current from the AC supply.
However, some type of sensing arrangement needs to be provided in order to notify the processor of the status of the connection between the adapter and the electronic device, that is, whether the adapter is plugged into (i.e., electrically connected to) the power receiving socket of the electronic device or not.